Amyotrophic Lateral Sclerosis Panel

Summary
Is a 35 gene panel that includes assessment of non-coding variants.

Is ideal for patients with a clinical suspicion or diagnosis of amyotrophic lateral sclerosis (ALS).

This panel does not cover the expansion of a hexanucleotide repeat in a non-coding region of C9orf72.

Analysis methods
  • PLUS
Availability
4 weeks
Number of genes
35
Test code
NE2201
Panel tier
Tier 1
CPT Code *
81403, 81404, 81405 x2, 81406 x9, 81407 x2, 81479
* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Summary

The Blueprint Genetics Amyotrophic Lateral Sclerosis Panel (test code NE2201):

Read about our accreditations, certifications and CE-marked IVD medical devices here.

This panel covers genes implicated in patients with ALS and frontotemporal dementia, *BSCL2*-related neurologic disorders, *DCTN1*-related distal hereditary motor neuronopathy type VIIB, *GBE1*-related adult polyglucosan body disease, and inclusion body myopathy associated with Paget disease of bone and/or frontotemporal dementia (IBMPFD).

ICD Codes

Refer to the most current version of ICD-10-CM manual for a complete list of ICD-10 codes.

Sample Requirements

  • Blood (min. 1ml) in an EDTA tube
  • Extracted DNA, min. 2 μg in TE buffer or equivalent
  • Saliva (Please see Sample Requirements for accepted saliva kits)

Label the sample tube with your patient’s name, date of birth and the date of sample collection.

We do not accept DNA samples isolated from formalin-fixed paraffin-embedded (FFPE) tissue. In addition, if the patient is affected with a hematological malignancy, DNA extracted from a non-hematological source (e.g. skin fibroblasts) is strongly recommended.

Please note that, in rare cases, mitochondrial genome (mtDNA) variants may not be detectable in blood or saliva in which case DNA extracted from post-mitotic tissue such as skeletal muscle may be a better option.

Read more about our sample requirements here.

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease characterized by the selective loss of motor neurons in the motor cortex, brain stem, and spinal cord. The dysfunction and loss of these neurons results in muscle weakness, atrophy and eventually paralysis of limb, bulbar and respiratory muscles. The prevalence of ALS is 1-9 per 100,000. A majority of ALS occurs in individuals with no family history of ALS. Familial ALS is most frequently inherited in an autosomal dominant disorder. Less frequently, it can be inherited in an autosomal recessive or X-linked fashion.

Genes in the Amyotrophic Lateral Sclerosis Panel and their clinical significance

To view complete table content, scroll horizontally.

Gene Associated phenotypes Inheritance ClinVar HGMD
ALS2 Amyotrophic lateral sclerosis, Spastic paralysis AR 33 68
ANG Amyotrophic lateral sclerosis AD 8 37
ATL1 Spastic paraplegia, Neuropathy, hereditary sensory AD 29 84
BSCL2 Lipodystrophy, congenital generalized, Encephalopathy, progressive, Neuropathy, distal hereditary motor, type VA, Charcot-Marie-Tooth disease type 2, Silver syndrome, Silver spastic paraplegia syndrome, Spastic paraplegia 17 AD/AR 34 50
CHCHD10 Myopathy, isolated mitochondrial, Frontotemporal dementia and/or amyotrophic lateral sclerosis 2, Spinal muscular atrophy, Jokela type AD 4 26
CHMP2B Amyotrophic lateral sclerosis, CHMP2B-related, Frontotemporal dementia AD 6 21
DCTN1 Perry syndrome, Neuropathy, distal hereditary motor AD 10 52
FIG4 Amyotrophic lateral sclerosis, Polymicrogyria, bilateral occipital, Yunis-Varon syndrome, Charcot-Marie-Tooth disease AD/AR 34 69
FUS Amyotrophic lateral sclerosis, Essential tremor AD/AR 22 111
GBE1 Glycogen storage disease AR 36 70
GRN Frontotemporal lobar degeneration with TDP43 inclusions, GRN-related, Neuronal ceroid lipofuscinosis AD/AR 43 214
HEXA Tay-Sachs disease, GM2-gangliosidosis, Hexosaminidase A deficiency AR 128 194
HNRNPA1* Amyotrophic lateral sclerosis, Inclusion body myopathy with early-onset Paget disease AD 20 11
HSPD1* Spastic paraplegia, Leukodystrophy, hypomyelinating AD/AR 5 5
KIAA0196 Spastic paraplegia, Ritscher-Schinzel syndrome (3C syndrome) AD/AR 15 18
KIF5A Spastic paraplegia AD 18 62
MATR3* Amyotrophic lateral sclerosis 21 AD 4 16
OPTN Glaucoma, open angle, Glaucoma, normal tension, Amyotrophic lateral sclerosis 12 AD 13 61
PFN1 Amyotrophic lateral sclerosis 18 AD 5 8
PRF1 Lymphoma, non-Hodgkin, Aplastic anemia, adult-onset, Hemophagocytic lymphohistiocytosis AR 24 183
REEP1 Spastic paraplegia, Distal hereditary motor neuronopathy AD 16 60
SETX Ataxia with oculomotor apraxia, Amyotrophic lateral sclerosis, juvenile, Spinocerebellar ataxia AD/AR 36 210
SLC52A2 Brown-Vialetto-Van Laere syndrome AR 27 25
SLC52A3 Fazio-Londe disease, Brown-Vialetto-Van Laere syndrome AR 30 42
SOD1 Amyotrophic lateral sclerosis, Keratoconus AD/AR 40 215
SPAST Spastic paraplegia AD 193 723
SPG11 Spastic paraplegia, Amyotrophic lateral sclerosis, Charcot-Marie-Tooth disease AR 162 274
SPG20 Spastic paraplegia (Troyer syndrome) AR 9 7
SQSTM1 Paget disease of bone, Frontotemporal dementia and/or amyotrophic lateral sclerosis 3, Myopathy, distal, with rimmed vacuoles, Neurodegeneration with ataxia, dystonia, and gaze palsy, childhood-onset AD/AR 10 97
TARDBP* Amyotrophic lateral sclerosis AD 20 69
TIA1 Welander distal myopathy AD 1 13
TUBA4A Amyotrophic lateral sclerosis 22 AD 6 13
UBQLN2 Amyotrophic lateral sclerosis XL 5 31
VAPB Amyotrophic lateral sclerosis, Spinal muscular atrophy, late-onset, Finkel AD 2 9
VCP Amyotrophic lateral sclerosis, Inclusion body myopathy with early-onset Paget disease, Charcot-Marie-Tooth disease AD 17 61
#

The gene has suboptimal coverage (means <90% of the gene’s target nucleotides are covered at >20x with mapping quality score (MQ>20) reads), and/or the gene has exons listed under Test limitations section that are not included in the panel as they are not sufficiently covered with high quality sequence reads.

*

Some, or all, of the gene is duplicated in the genome. Read more.

The sensitivity to detect variants may be limited in genes marked with an asterisk (*) or number sign (#). Due to possible limitations these genes may not be available as single gene tests.

Gene refers to the HGNC approved gene symbol; Inheritance refers to inheritance patterns such as autosomal dominant (AD), autosomal recessive (AR), mitochondrial (mi), X-linked (XL), X-linked dominant (XLD) and X-linked recessive (XLR); ClinVar refers to the number of variants in the gene classified as pathogenic or likely pathogenic in this database (ClinVar); HGMD refers to the number of variants with possible disease association in the gene listed in Human Gene Mutation Database (HGMD). The list of associated, gene specific phenotypes are generated from CGD or Mitomap databases.

Non-coding variants covered by Amyotrophic Lateral Sclerosis Panel

To view complete table content, scroll horizontally.

Gene Genomic location HG19 HGVS RefSeq RS-number
BSCL2 Chr11:62470032 c.405-11A>G NM_001122955.3
FUS Chr16:31202807 c.*48G>A NM_004960.3 rs376510148
FUS Chr16:31202818 c.*59G>A NM_004960.3
FUS Chr16:31202863 c.*105dupT NM_004960.3
FUS Chr16:31202867 c.*108C>T NM_004960.3 rs780606789
FUS Chr16:31202869 c.*110G>A NM_004960.3
FUS Chr16:31202891 c.*132C>A NM_004960.3 rs565540429
FUS Chr16:31202949 c.*190C>A NM_004960.3
GBE1 Chr3:81542964 c.2053-3358_2053-3350delGTGTGGTGGinsTGTTTTTTACATGACAGGT NM_000158.3 rs869320698
GRN Chr17:42422701 c.-9A>G NM_002087.2
GRN Chr17:42422705 c.-8+3A>T NM_002087.2 rs63751020
GRN Chr17:42422705 c.-8+3A>G NM_002087.2
GRN Chr17:42422707 c.-8+5G>C NM_002087.2 rs63750313
HEXA Chr15:72640009 c.1146+18A>G NM_000520.4
MATR3 Chr5:138611841 c.-339+2T>A NM_199189.2 rs539017488
SLC52A2 Chr8:145582843 c.-110-1G>A NM_024531.4
SOD1 Chr21:33038893 c.239+62T>C NM_000454.4
SOD1 Chr21:33039727 c.357+43_357+46delTACA NM_000454.4
SOD1 Chr21:33040480 c.358-304C>G NM_000454.4
SOD1 Chr21:33040773 c.358-11A>G NM_000454.4 rs369600566
TARDBP Chr1:11082794 c.*83T>C NM_007375.3 rs80356744
TARDBP Chr1:11083408 c.*697G>A NM_007375.3 rs387906334
VCP Chr9:35072710 c.-360G>C NM_007126.3

Test Strengths

This panel covers genes implicated in patients with ALS and frontotemporal dementia, *BSCL2*-related neurologic disorders, *DCTN1*-related distal hereditary motor neuronopathy type VIIB, *GBE1*-related adult polyglucosan body disease, and inclusion body myopathy associated with Paget disease of bone and/or frontotemporal dementia (IBMPFD).

The strengths of this test include:

  • CAP accredited laboratory
  • CLIA-certified personnel performing clinical testing in a CLIA-certified laboratory
  • Powerful sequencing technologies, advanced target enrichment methods and precision bioinformatics pipelines ensure superior analytical performance
  • Careful construction of clinically effective and scientifically justified gene panels
  • Some of the panels include the whole mitochondrial genome (please see the Panel Content section)
  • Our Nucleus online portal providing transparent and easy access to quality and performance data at the patient level
  • ~2,000 non-coding disease causing variants in our clinical grade NGS assay for panels (please see ‘Non-coding disease causing variants covered by this panel’ in the Panel Content section)
  • Our rigorous variant classification scheme
  • Our systematic clinical interpretation workflow using proprietary software enabling accurate and traceable processing of NGS data
  • Our comprehensive clinical statements

Test Limitations

This panel does not cover the expansion of a hexanucleotide repeat in a non-coding region of *C9orf72*. Genes with partial, or whole gene, segmental duplications in the human genome are marked with an asterisk (*) if they overlap with the UCSC pseudogene regions. The technology may have limited sensitivity to detect variants in genes marked with these symbols (please see the Panel content table above).

This test does not detect the following:

  • Complex inversions
  • Gene conversions
  • Balanced translocations
  • Some of the panels include the whole mitochondrial genome but not all (please see the Panel Content section)
  • Repeat expansion disorders unless specifically mentioned
  • Non-coding variants deeper than ±20 base pairs from exon-intron boundary unless otherwise indicated (please see above Panel Content / non-coding variants covered by the panel).

This test may not reliably detect the following:

  • Low level mosaicism in nuclear genes (variant with a minor allele fraction of 14.6% is detected with 90% probability)
  • Stretches of mononucleotide repeats
  • Low level heteroplasmy in mtDNA (>90% are detected at 5% level)
  • Indels larger than 50bp
  • Single exon deletions or duplications
  • Variants within pseudogene regions/duplicated segments
  • Some disease causing variants present in mtDNA are not detectable from blood, thus post-mitotic tissue such as skeletal muscle may be required for establishing molecular diagnosis.

The sensitivity of this test may be reduced if DNA is extracted by a laboratory other than Blueprint Genetics.

For additional information, please refer to the Test performance section.

The genes on the panel have been carefully selected based on scientific literature, mutation databases and our experience.

Our panels are sectioned from our high-quality, clinical grade NGS assay. Please see our sequencing and detection performance table for details regarding our ability to detect different types of alterations (Table).

Assays have been validated for various sample types including EDTA-blood, isolated DNA (excluding from formalin fixed paraffin embedded tissue), saliva and dry blood spots (filter cards). These sample types were selected in order to maximize the likelihood for high-quality DNA yield. The diagnostic yield varies depending on the assay used, referring healthcare professional, hospital and country. Plus analysis increases the likelihood of finding a genetic diagnosis for your patient, as large deletions and duplications cannot be detected using sequence analysis alone. Blueprint Genetics’ Plus Analysis is a combination of both sequencing and deletion/duplication (copy number variant (CNV)) analysis.

The performance metrics listed below are from an initial validation performed at our main laboratory in Finland. The performance metrics of our laboratory in Marlborough, MA, are equivalent.

Performance of Blueprint Genetics high-quality, clinical grade NGS sequencing assay for panels.

Sensitivity % (TP/(TP+FN) Specificity %
Single nucleotide variants 99.89% (99,153/99,266) >99.9999%
Insertions, deletions and indels by sequence analysis
1-10 bps 99.2% (7,745/7,806) >99.9999%
11-50 bps 99.13% (2,524/2,546) >99.9999%
Copy number variants (exon level dels/dups)
1 exon level deletion (heterozygous) 100% (20/20) NA
1 exon level deletion (homozygous) 100% (5/5) NA
1 exon level deletion (het or homo) 100% (25/25) NA
2-7 exon level deletion (het or homo) 100% (44/44) NA
1-9 exon level duplication (het or homo) 75% (6/8) NA
Simulated CNV detection
5 exons level deletion/duplication 98.7% 100.00%
Microdeletion/-duplication sdrs (large CNVs, n=37))
Size range (0.1-47 Mb) 100% (25/25)
     
The performance presented above reached by Blueprint Genetics high-quality, clinical grade NGS sequencing assay with the following coverage metrics
     
Mean sequencing depth 143X
Nucleotides with >20x sequencing coverage (%) 99.86%

Performance of Blueprint Genetics Mitochondrial Sequencing Assay.

Sensitivity % Specificity %
ANALYTIC VALIDATION (NA samples; n=4)
Single nucleotide variants
Heteroplasmic (45-100%) 100.0% (50/50) 100.0%
Heteroplasmic (35-45%) 100.0% (87/87) 100.0%
Heteroplasmic (25-35%) 100.0% (73/73) 100.0%
Heteroplasmic (15-25%) 100.0% (77/77) 100.0%
Heteroplasmic (10-15%) 100.0% (74/74) 100.0%
Heteroplasmic (5-10%) 100.0% (3/3) 100.0%
Heteroplasmic (<5%) 50.0% (2/4) 100.0%
CLINICAL VALIDATION (n=76 samples)
All types
Single nucleotide variants n=2026 SNVs
Heteroplasmic (45-100%) 100.0% (1940/1940) 100.0%
Heteroplasmic (35-45%) 100.0% (4/4) 100.0%
Heteroplasmic (25-35%) 100.0% (3/3) 100.0%
Heteroplasmic (15-25%) 100.0% (3/3) 100.0%
Heteroplasmic (10-15%) 100.0% (9/9) 100.0%
Heteroplasmic (5-10%) 92.3% (12/13) 99.98%
Heteroplasmic (<5%) 88.9% (48/54) 99.93%
Insertions and deletions by sequence analysis n=40 indels
Heteroplasmic (45-100%) 1-10bp 100.0% (32/32) 100.0%
Heteroplasmic (5-45%) 1-10bp 100.0% (3/3) 100.0%
Heteroplasmic (<5%) 1-10bp 100.0% (5/5) 99,997%
SIMULATION DATA /(mitomap mutations)
Insertions, and deletions 1-24 bps by sequence analysis; n=17
Homoplasmic (100%) 1-24bp 100.0% (17/17) 99.98%
Heteroplasmic (50%) 100.0% (17/17) 99.99%
Heteroplasmic (25%) 100.0% (17/17) 100.0%
Heteroplasmic (20%) 100.0% (17/17) 100.0%
Heteroplasmic (15%) 100.0% (17/17) 100.0%
Heteroplasmic (10%) 94.1% (16/17) 100.0%
Heteroplasmic (5%) 94.1% (16/17) 100.0%
Copy number variants (separate artifical mutations; n=1500)
Homoplasmic (100%) 500 bp, 1kb, 5 kb 100.0% 100.0%
Heteroplasmic (50%) 500 bp, 1kb, 5 kb 100.0% 100.0%
Heteroplasmic (30%) 500 bp, 1kb, 5 kb 100.0% 100.0%
Heteroplasmic (20%) 500 bp, 1kb, 5 kb 99.7% 100.0%
Heteroplasmic (10%) 500 bp, 1kb, 5 kb 99.0% 100.0%
The performance presented above reached by following coverage metrics at assay level (n=66)
Mean of medians Median of medians
Mean sequencing depth MQ0 (clinical) 18224X 17366X
Nucleotides with >1000x MQ0 sequencing coverage (%) (clinical) 100%
rho zero cell line (=no mtDNA), mean sequencing depth 12X

The target region for each gene includes coding exons and ±20 base pairs from the exon-intron boundary. In addition, the panel includes non-coding and regulatory variants if listed above (Non-coding variants covered by the panel). Some regions of the gene(s) may be removed from the panel if specifically mentioned in the ‘Test limitations” section above. If the test includes the mitochondrial genome the target region gene list contains the mitochondrial genes. The sequencing data generated in our laboratory is analyzed with our proprietary data analysis and annotation pipeline, integrating state-of-the art algorithms and industry-standard software solutions. Incorporation of rigorous quality control steps throughout the workflow of the pipeline ensures the consistency, validity and accuracy of results. Our pipeline is streamlined to maximize sensitivity without sacrificing specificity. We have incorporated a number of reference population databases and mutation databases including, but not limited, to 1000 Genomes Project, gnomAD, ClinVar and HGMD into our clinical interpretation software to make the process effective and efficient. For missense variants, in silico variant prediction tools such as  SIFT, PolyPhen,MutationTaster are used to assist with variant classification. Through our online ordering and statement reporting system, Nucleus, ordering providers have access to the details of the analysis, including patient specific sequencing metrics, a gene level coverage plot and a list of regions with suboptimal coverage (<20X for nuclear genes and <1000X for mtDNA) if applicable. This reflects our mission to build fully transparent diagnostics where ordering providers can easily visualize the crucial details of the analysis process.

We provide customers with the most comprehensive clinical report available on the market. Clinical interpretation requires a fundamental understanding of clinical genetics and genetic principles. At Blueprint Genetics, our PhD molecular geneticists, medical geneticists, and clinical consultants prepare the clinical statement together by evaluating the identified variants in the context of the phenotypic information provided in the requisition form. Our goal is to provide clinically meaningful statements that are understandable for all medical professionals regardless of whether they have formal training in genetics.

Variant classification is the cornerstone of clinical interpretation and resulting patient management decisions. Our classifications follow the ACMG guideline 2015.

The final step in the analysis is orthogonal confirmation. Sequence and copy number variants classified as pathogenic, likely pathogenic, and variants of uncertain significance (VUS) are confirmed using bi-directional Sanger sequencing or by orthogonal methods such as qPCR/ddPCR when they do not meet our stringent NGS quality metrics for a true positive call.

Our clinical statement includes tables for sequencing and copy number variants that include basic variant information (genomic coordinates, HGVS nomenclature, zygosity, allele frequencies, in silico predictions, OMIM phenotypes, and classification of the variant). In addition, the statement includes detailed descriptions of the variant, gene, and phenotype(s) including the role of the specific gene in human disease, the mutation profile, information about the gene’s variation in population cohorts, and detailed information about related phenotypes. We also provide links to the references, abstracts, and variant databases used to help ordering providers further evaluate the reported findings if desired. The conclusion summarizes all of the existing information and provides our rationale for the classification of the variant.

Identification of pathogenic or likely pathogenic variants in dominant disorders or their combinations in different alleles in recessive disorders are considered molecular confirmation of the clinical diagnosis. In these cases, family member testing can be used for risk stratification. We do not recommend using variants of uncertain significance (VUS) for family member risk stratification or patient management. Genetic counseling is recommended.

Our interpretation team analyzes millions of variants from thousands of individuals with rare diseases. Our internal database and our understanding of variants and related phenotypes increases with every case analyzed. Our laboratory is therefore well-positioned to re-classify previously reported variants as new information becomes available. If a variant previously reported by Blueprint Genetics is re-classified, our laboratory will issue a follow-up statement to the original ordering healthcare provider at no additional cost, according to our latest follow-up reporting policy.